I installed the Sillen hi-flow box on my coupe this past Saturday, and I've got a couple questions for the community here (I've searched, but apologies in advance if they've been addressed in other posts):

1. Is there supposed to be a bit of a gap running down the top of the right side of the Stillen air box and the body? On the right side of mine it appears that there is a small gap on the right side of the air box (near where the box bolts down to the strut)...so you can see the filter through both the forward scoop and this little gap that runs down the right side of the box. Is this normal?

2. Since I've installed it, there seems to have been an extreme dropoff in gas mileage...what's been everyone's experience with the gas mileage after installing the Stillen? I can perhaps understand a bit of a dropoff, as I can see where more air intake would require the car to burn more fuel, but this I've experienced a pretty dramatic drop. Does resetting the ECU help with this issue? What's been others' experience?

Thanks in advance for all replies...

Brilliant Silver Coupe | Willow | 6MT | Aero | Premium

 

Mine has a gap too...it just allows maximum airflow into the car...I also have an old Altima with a Stillen intake, and there's no air box at all on mine..jst the filter. so I don't think it's a big deal. The gas milage on my G also dropped a lot too, but I've driven about 400-500 miles since I put my Stillen on, and I'm starting to see mine creep back up...you should really reset the ecu (through the disconnect battery method, not the magic pedal trick), that will get the ecu learning a little faster...I don't think you can get the gas milage back to what it would be with the stock filter...can you? Does anyone else know?